The Effects of Transcranial Direct Current Stimulation and Exercise on Salivary S100B Protein Indicated Blood-Brain Barrier Permeability: A Pilot Study.

OBJECTIVE: This study aimed to assess the effect of transcranial direct current stimulation (tDCS) and exercise on blood-brain barrier (BBB) permeability in humans as assessed through the quantification of the salivary protein biomarker S100B. It was hypothesized that active tDCS would induce a significant increase in salivary S100B concentration when compared with sham stimulation and no stimulation. It also was hypothesized that the increase in salivary S100B concentration would be greater after active tDCS and exercise than after tDCS or exercise alone. MATERIALS AND METHODS: A total of 13 healthy adults (five male, eight female), ranging in age from 21 to 32 years, underwent three experimental conditions (active tDCS, sham tDCS, inactive control). To assess exercise- and tDCS-induced changes in BBB permeability, S100B in saliva was measured. Saliva samples were taken before tDCS, after tDCS, and immediately after a ramped cycling time-to-exhaustion (TTE) task. Active tDCS involved the application of anodal stimulation over the primary motor cortex for 20 minutes at 2 mA. RESULTS: S100B concentrations in the control condition did not differ significantly from the active condition (estimate = 0.10, SE = 0.36, t = 0.27, p = 0.79) or the sham condition (estimate = 0.33, SE = 0.36, t = 0.89, p = 0.38). Similarly, S100B concentrations at baseline did not differ significantly from post-intervention (estimate = -0.35, SE = 0.34, t = -1.03, p = 0.31) or post-TTE (estimate = 0.66, SE = 0.34, t = 1.93, p = 0.06). CONCLUSIONS: This research provides novel insight into the effect of tDCS and exercise on S100B-indicated BBB permeability in humans. Although the effects of tDCS were not significant, increases in salivary S100B after a fatiguing cycling task may indicate exercise-induced changes in BBB permeability.

Large area stimulated emission luminescent solar concentrators modelled using detailed balance consistent rate equations.

Stimulated emission luminescent solar concentrators (SELSCs) have the potential to reduce escape cone losses in luminescent solar concentrators (LSCs). However, a functional SELSC is yet to be demonstrated. Previous numerical studies and detailed balance limits provide guidance, but they also contradict and likely overestimate performance and underestimate requirements. In this work, we introduce a rate-equation model with inversion requirements compatible with detailed balance limits and apply this model to the numerical modelling of window-sized SELSCs. We find that the optimal pump photon energy for both LSCs and SELSCs is 1.35 eV and the potential improvement of SELSCs over LSCs is found to be 19.3%. The efficiencies found are much lower than those specified in previous work due to the increase in Stokes shift required for a highly luminescent material. We also find that SELSCs are more attractive at higher matrix losses, that emission linewidths <0.05  eV are desirable, and that SELSC devices can potentially achieve performance equal to LSCs at low illumination levels and simultaneously exceed it by up to 16.5% at 1-sun illumination.

Detailed balance limits for inversion in solar-pumped lasers and allied systems.

Solar-pumped lasers and optical amplifiers continue to draw research interest with advances in nanomaterials science and technology. Establishing accurate detailed balance limits for inversion in these systems is essential. In this Letter, we re-examine the threshold limits for inversion in broadband-pumped lasers, with reference to those provided by Roxlo and Yablonvitch [Opt. Lett.8, 271 (1983)OPLEDP0146-959210.1364/OL.8.000271], where they determined the minimum Stokes shift and the minimum ratio of pump band to emission band absorption constants-based on independent consideration of the emission at pump and emission frequencies. In contrast, the derivation here simultaneously accounts for emission in both the pump and emission bands, which in turn leads to a single consolidated inequality that serves to establish the revised threshold requirements for inversion. Upon applying this new unified relationship to solar-pumped devices, a large increase in the minimum required Stokes shifts for 1-sun devices, particularly at larger pump energies and smaller ratios of αp0/αe0, is found. The maximum possible efficiencies of solar-pumped devices are calculated using this new relation.

Images depicting human pain increase exercise-induced pain and impair endurance cycling performance.

The current study investigated whether viewing images of others in pain influences exercise-induced pain (EIP) and cycling performance. Twenty-one recreational cyclists attended five laboratory visits. The first two visits involved measuring participants' maximal aerobic capacity and familiarized participants to the fixed power (FP) and 16.1 km cycling time trial (TT) tasks. The FP task required participants to cycle at 70% of their maximal aerobic power for 10-minutes. In the subsequent three visits, participants performed the FP and TT tasks after viewing pleasant, painful or neutral images. Participants rated the subset of painful images as more painful than the pleasant and neutral images; with no difference in the pain ratings of the pleasant and neutral images. In the FP task, EIP ratings were higher following painful compared to pleasant images, while no differences in EIP were observed between any other condition . In the TT, performance did not differ between the pleasant and neutral conditions. However, TT performance was reduced after viewing painful images compared to neutral or pleasant images. HR, B[La], perceived exertion and EIP did not differ between the three conditions. These results suggest that viewing painful images decreases TT performance and increases pain during fixed intensity cycling. Abbreviations: EIP: Exercise Induced Pain; FP: Fixed Power; TT: Time Trial; HR:Heart Rate; B[La]: Blood Lactate; RPE: Rating of Perceived Exertion; IAPS: International Affective Picture System; PO: Power Output.

The Impact of Cognitive, Physical, and Psychological Stressors on Subsequent Cognitive Performance.

OBJECTIVE: To quantify the impact of performing challenging cognitive, physical and psychological tasks on subsequent cognitive performance, and whether differences in performance are predicted by psychological variables. BACKGROUND: Successful performance in many occupations depends on resilient cognition: the degree to which cognitive functions can withstand, or are resilient to, the effects of stress. Several studies have examined the effect of individual stressors on cognition; however, the capacity to compare different types of stress across studies is limited. METHOD: Fifty-eight participants completed cognitive, physical, psychological and control interventions, immediately preceded, and followed, by a battery of cognitive tasks. Self-efficacy and cognitive appraisal were reported at baseline. Perceived stress was recorded post-intervention. Subjective workload was recorded for each cognitive battery and intervention. RESULTS: Cognitive performance was impaired by the cognitive, physical and psychological interventions, with the greatest effect following the cognitive intervention. The subjective workload reported for the post-intervention cognitive battery was higher following the cognitive and physical interventions. Neither self-efficacy, cognitive appraisal, perceived stress nor subjective workload of the intervention strongly predicted post-intervention performance. CONCLUSION: Given the differences among interventions and cognitive domains, it appears that challenges to resilient cognition are broad and varied, and the mechanism(s) by which impairment occurs is complex. APPLICATION: Considering the increase in subjective workload for the post-intervention cognitive battery, a combination of subjective and objective measures of cognitive performance monitoring should be considered.

Shock Index as a Predictor of Morbidity and Mortality in Pediatric Trauma Patients.

OBJECTIVES: Compared with unadjusted shock index (SI) (heart rate/systolic blood pressure), age-adjusted SI improves identification of negative outcomes after injury in pediatric patients. We aimed to further evaluate the utility of age-adjusted SI to predict negative outcomes in pediatric trauma. METHODS: We performed an analysis of patients younger than 15 years using the National Trauma Data Bank. Elevated SI was defined as high normal heart rate divided by low-normal blood pressure for age. Our primary outcome measure was mortality. Secondary outcomes included need for a blood transfusion, ventilation, any operating room/interventional radiology procedures, and intensive care unit stay. Multiple logistic regressions were performed. RESULTS: Twenty-eight thousand seven hundred forty-one cases met the study criteria. The overall mortality rate was 0.7%, and 1.7% had an elevated SI. Patients with an elevated SI were more likely (P < 0.001) to require blood transfusion, ventilation, an operating room/interventional radiology procedure, or an intensive care unit stay. An elevated SI was the strongest predictor for mortality (odds ratio [OR] 22.0) in pediatric trauma patients compared with hypotension (OR, 12.6) and tachycardia (OR, 2.6). CONCLUSIONS: Elevated SI is an accurate and specific predictor of morbidity and mortality in pediatric trauma patients and is superior to tachycardia or hypotension alone for predicting mortality.

Patterned Optoelectronic Tweezers: A New Scheme for Selecting, Moving, and Storing Dielectric Particles and Cells.

Optical micromanipulation has become popular for a wide range of applications. In this work, a new type of optical micromanipulation platform, patterned optoelectronic tweezers (p-OET), is introduced. In p-OET devices, the photoconductive layer (that is continuous in a conventional OET device) is patterned, forming regions in which the electrode layer is locally exposed. It is demonstrated that micropatterns in the photoconductive layer are useful for repelling unwanted particles/cells, and also for keeping selected particles/cells in place after turning off the light source, minimizing light-induced heating. To clarify the physical mechanism behind these effects, systematic simulations are carried out, which indicate the existence of strong nonuniform electric fields at the boundary of micropatterns. The simulations are consistent with experimental observations, which are explored for a wide variety of geometries and conditions. It is proposed that the new technique may be useful for myriad applications in the rapidly growing area of optical micromanipulation.

Escape from an Optoelectronic Tweezer Trap: experimental results and simulations.

Optoelectronic tweezers (OET) are a microsystem actuation technology capable of moving microparticles at mm s-1 velocities with nN forces. In this work, we analyze the behavior of particles manipulated by negative dielectrophoresis (DEP) forces in an OET trap. A user-friendly computer interface was developed to generate a circular rotating light pattern to control the movement of the particles, allowing their force profiles to be conveniently measured. Three-dimensional simulations were carried out to clarify the experimental results, and the DEP forces acting on the particles were simulated by integrating the Maxwell stress tensor. The simulations matched the experimental results and enabled the determination of a new "hopping" mechanism for particle-escape from the trap. As indicated by the simulations, there exists a vertical DEP force at the edge of the light pattern that pushes up particles to a region with a smaller horizontal DEP force. We propose that this phenomenon will be important to consider for the design of OET micromanipulation experiments for a wide range of applications.

Outcome of Pediatric Forearm Fracture Reductions Performed by Pediatric Emergency Medicine Providers Compared With Reductions Performed by Orthopedic Surgeons: A Retrospective Cohort Study.

OBJECTIVE: The aim of this study was to describe the outcome differences between board-certified orthopedists and pediatric emergency medicine (PEM) physicians conducting forearm fracture reductions. METHODS: We performed an analysis of patients between 1 and 14 years of age who presented to the emergency department (ED) with a forearm fracture requiring reduction. Data collected included reducing provider (PEM or orthopedist) and prereduction, postreduction, and follow-up fracture angles and displacements of both radius and ulna. We collected costs of care, both in the ED and at follow-up, as well as length-of-stay data. χ Tests and Fisher exact test compared associations between categorical variables; 2-sample t tests compared the PEM and orthopedic groups. Regression models were used to control for injury severity confounders. RESULTS: Of the 222 fractures, orthopedists reduced 135, and PEM doctors reduced 87. Based on fracture angle and displacement, the orthopedic group tended to have slightly more complicated cases. After adjusting for age and time to follow-up, fractures reduced by orthopedists were less likely to require remanipulation (adjusted odds ratio, 0.30; P = 0.020). The PEM group had a significantly lower length of stay (59.4 minutes shorter; P < 0.001) and a small overall saving in charges ($273.90; P = 0.47). CONCLUSIONS: Orthopedists performed better in maintaining fracture reductions compared with PEM physicians but lengthened the ED stay for our patients. There was no significant difference in cost.

Influence of luminescent material properties on stimulated emission luminescent solar concentrators (SELSCs) using a 4-level system.

The effect of various design and material parameters on the efficiency of stimulated emission-based luminescent solar concentrators (SELSCs) is studied numerically using a 4-level luminescent material containing concentrator. It is shown that the most efficient SELSCs have emission wavelengths of 1.5-1.8 µm, with a strong dependence on the Stokes shift. Depending on the parameters of the system, spontaneous emission is shown to nevertheless account for a significant fraction of potential energy generation. Assuming a propagation loss constant of -0.1m-1, and a refractive index of 1.5, the optimal length of an SELSC is found to be ~1.5m. Given these losses and an efficiency target of 10% greater than traditional LSCs, the required material emission linewidth varies from 10 to 100nm, with maximum thicknesses of 3-30 µm. Further, when reflection and propagation losses are considered, a single laser pass is preferred over multiple passes. It is also shown that SELSCs are significantly less sensitive to luminescent quantum efficiency when compared to conventional LSCs due to the increased radiative emission rate.

Increased conditioned pain modulation in athletes.

The potential relationship between physical activity and endogenous pain modulatory capacity remains unclear. Therefore, the aim of the current study was to compare the pain modulatory responses of athletes and non-athletes. Conditioned pain modulation (CPM) was assessed in 15 athletes and 15 non-athletes at rest. Participation was restricted to pain-free males between 18 and 40 years of age. To measure CPM capacity, a sequential CPM testing protocol was implemented, whereby a test stimulus (pressure pain threshold [PPT]) was presented before and immediately after a conditioning stimulus (4-min cold-pressor test). Pain intensity ratings were obtained at 15-s intervals throughout the cold-pressor task using a numerical rating scale. Athletes demonstrated higher baseline PPTs compared to non-athletes (P = .03). Athletes also gave lower mean (P < .001) and maximum (P < .001) pain intensity ratings in response to the conditioning stimulus. The conditioning stimulus had a stronger inhibitory effect on the test stimulus in athletes, showing enhanced CPM in athletes compared to non-athletes (P < .05). This finding of enhanced CPM in athletes helps clarify previous mixed findings. Potential implications for exercise performance and injury are discussed.

Examining the relationship between endogenous pain modulation capacity and endurance exercise performance.

The aim of the current study was to examine the relationship between pain modulatory capacity and endurance exercise performance. Twenty-seven recreationally active males between 18 and 35 years of age participated in the study. Pain modulation was assessed by examining the inhibitory effect of a noxious conditioning stimulus (cuff occlusion) on the perceived intensity of a second noxious stimulus (pressure pain threshold). Participants completed two, maximal voluntary contractions followed by a submaximal endurance time task. Both performance tasks involved an isometric contraction of the non-dominant leg. The main analysis uncovered a correlation between pain modulatory capacity and performance on the endurance time task (r = -.425, p = .027), such that those with elevated pain modulation produced longer endurance times. These findings are the first to demonstrate the relationship between pain modulation responses and endurance exercise performance.

Racial Differences in Pediatric Emergency Department Triage Scores.

BACKGROUND: Racial disparities are frequently reported in emergency department (ED) care. OBJECTIVES: To examine racial differences in triage scores of pediatric ED patients. We hypothesized that racial differences existed but could be explained after adjusting for sociodemographic and clinical factors. METHODS: We examined all visits to two urban, pediatric EDs between August 2009 and March 2010. Demographic and clinical data were electronically extracted from the medical record. We used logistic regression to analyze racial differences in triage scores, controlling for possible covariates. RESULTS: There were 54,505 ED visits during the study period, with 7216 (13.2%) resulting in hospital admission. White patients accounted for 36.4% of visits, African Americans 28.5%, Hispanics 18.0%, Asians 4.1%, and American Indians 1.8%. After adjusting for potential confounders, African American (adjusted odds ratio [aOR] 1.89, 95% confidence interval [CI] 1.69-2.12), Hispanic (aOR 1.77, 95% CI 1.55-2.02), and American Indian (aOR 2.57, 95% CI 1.80-3.66) patients received lower-acuity triage scores than Whites. In three out of four subgroup analyses based on presenting complaints (breathing difficulty, abdominal pain, fever), African Americans and Hispanics had higher odds of receiving low-acuity triage scores. No racial differences were detected for patients with presenting complaints of laceration/head injury/arm injury. However, among patients admitted to the hospital, African Americans (aOR 1.47, 95% CI 1.13-1.90) and Hispanics (aOR 1.71, CI 1.22-2.39) received lower-acuity triage scores than Whites. CONCLUSION: After adjusting for available sociodemographic and clinical covariates, African American, Hispanic, and American Indian patients received lower-acuity triage scores than Whites.

Concussion Among Youth Skiers and Snowboarders: A Review of the National Trauma Data Bank From 2009 to 2010.

OBJECTIVE: There are limited data regarding concussion among youth skiers and snowboarders. The objective of this study was to examine the frequency of concussion among helmeted and unhelmeted youth skiers and snowboarders presenting to trauma centers. METHODS: Subjects 18 years or younger with a ski- or snowboard-related injury were studied using data from the National Trauma Data Bank from 2009 to 2010. We further selected those with head/neck injuries and stratified based on helmet status. Concussive injuries were identified from International Classification of Diseases, 9th Revision codes. Severity analysis was based on the Glasgow Coma Scale and Injury Severity Score. RESULTS: A total of 1001 subjects met inclusion criteria with 678 subjects having documented helmet status. Subjects 12 years or younger were more likely to use helmets compared to 13-18 year-olds (odds ratio, 2.21; 95% confidence interval [95% CI], 1.52-3.21). Skiers were more likely to use helmets compared to snowboarders (odds ratios, 1.60; 95% CI, 1.16-2.19). Snowboarders had a greater likelihood of concussion (estimated-ß, 2.1; 95% CI, 1.48-2.85) after adjusting for helmet status and age. There was no significant difference in the frequency of concussion among helmeted compared to unhelmeted subjects. Imputing missing values for helmets status had no effect on outcome for concussion. We found no difference in injury severity among helmeted compared to unhelmeted subjects. CONCLUSIONS: Among youth skiers and snowboarders who present to trauma centers with a head injury, the likelihood of that injury involving a concussion was not associated with helmet use.

The Relationship Between Pain and Interoception: A Systematic Review and Meta-Analysis.

Interoception refers to the ability to sense internal bodily sensations. Research suggests that dysfunctions in interoception may be implicated in the transition to chronic pain, however, little work has examined interoceptive ability in pain states. Therefore, this systematic review aimed to assess whether interoception is altered in individuals experiencing pain. Following a systematic search of 4 electronic databases from inception to February 2023, 28 studies were included. Outcomes of interoceptive accuracy, interoceptive sensibility, and interoceptive awareness were meta-analysed. The risk of bias was assessed, and the certainty of the evidence was evaluated. Meta-analyses indicated that those with chronic pain display reduced interoceptive accuracy and increased interoceptive sensibility. Subgroup analyses indicated that the change in interoceptive sensibility is dependent on the measure used, with those with chronic pain scoring higher on measures focusing on attention to bodily sensations, while also scoring lower on emotional reactivity. No difference in interoceptive awareness was observed between individuals with chronic pain and pain-free controls. Only one study was found that measured interoception in those experiencing acute pain, while another study recruited those experiencing recurrent pain. These findings suggest that while those with chronic pain self-report as more interoceptively aware, they are less accurate at detecting internal bodily signals. Further research investigating domains of interoception in those experiencing acute and recurrent pain is needed. Data should be interpreted with caution as the certainty of evidence was very low for all completed analyses. This review was registered on the PROSPERO International Prospective Register of Systematic Reviews (Registration ID = CRD42022318843). PERSPECTIVE: This review considered the relationship between interoception and pain and found that an individual's ability to accurately sense internal signals is decreased in those with chronic pain, despite them reporting being more aware of internal sensations. However, there remains little research examining interoception in non-chronic pain states.

Does initial length of stay impact 30-day readmission risk in pediatric asthma patients?

OBJECTIVES: Accountable care puts pressure on hospitals to manage care episodes. Initial length of stay (ILOS) and readmission risk are important elements of a care episode and measures of care quality. Understanding the association between these two measures can guide hospital efforts in managing care episodes. This study was designed to explore the association between ILOS and readmission risk in a cohort of pediatric asthma patients. MATERIALS AND METHODS: The sample cohort (n = 4965) consisted of all asthma patients discharged from Children's Hospitals and Clinics of Minnesota (CHC MN) from January 2008 through August 2012. Asthma discharges included cases with a principal diagnosis of asthma or certain respiratory cases with asthma listed as a secondary diagnosis. Multiple logistic regression was used to test associations, adjusting for covariates. RESULTS: Adjusting for covariates, we found no significant association between ILOS and readmission (OR: 1.04 [95% CI: 0.98-1.10]). Analyzing ILOS categorically by length of stay, one-day stays did not have a significantly higher readmission risk (OR:1.27 [95% CI: 0.87-1.85]) than two-day stays, which had the lowest observed readmission risk. Risk increased as ILOS exceeded two days but was not significantly different by day. We found no association when comparing the difference in actual versus expected ILOS and readmission risk (shorter than expected OR: 1.13 [95% CI: 0.74-1.71]; longer than expected OR: 0.97 [95% CI: 0.69-1.38]). CONCLUSIONS: Attempts to prolong ILOS would dramatically increase costs with little impact on readmissions. For example, increasing one-day visits to two-day visits would increase hospital patient days 38% (1870 d) in this cohort while decreasing total readmissions by 3.8% [95% CI: 3.6-4.0%]. Understanding the mechanisms that impact readmissions is essential in evaluating cost-effective approaches to improving patient outcomes and lowering the cost of care.

The effects of high-definition transcranial direct current stimulation on pain modulation and stress-induced hyperalgesia.

Background: The dorsolateral prefrontal cortex (DLPFC) has been implicated in the modulation of pain-related signals. Given this involvement, manipulation of the DLPFC through transcranial direct current stimulation (tDCS) may influence internal pain modulation and decrease pain sensitivity. Acute stress is also thought to affect pain, with increased pain sensitivity observed following the presentation of an acute stressor. Methods: A total of 40 healthy adults (50% male), ranging in age from 19 to 28 years (M = 22.13, SD = 1.92), were randomly allocated to one of two stimulation conditions (active and sham). High-definition tDCS (HD-tDCS) was applied for 10 min at 2 mA, with the anode placed over the left DLPFC. Stress was induced after HD-tDCS administration using a modified version of the Trier Social Stress Test. Pain modulation and sensitivity were assessed through the conditioned pain modulation paradigm and pressure pain threshold measurements, respectively. Results: Compared to sham stimulation, active stimulation produced a significant increase in pain modulation capacity. No significant change in pain sensitivity and stress-induced hyperalgesia was observed following active tDCS. Conclusion: This research shows novel evidence that anodal HD-tDCS over the DLPFC significantly enhances pain modulation. However, HD-tDCS had no effect on pain sensitivity or stress-induced hyperalgesia. The observed effect on pain modulation after a single dose of HD-tDCS over the DLPFC is a novel finding that informs further research into the utility of HD-tDCS in the treatment of chronic pain by presenting the DLPFC as an alternative target site for tDCS-induced analgesia.

Teamwork measure relates to provider experience, burnout, and intent to stay.

OBJECTIVES: To develop a brief teamwork measure and determine how teamwork relates to provider experience, burnout, and work intentions. STUDY DESIGN: Survey of clinicians. METHODS: We analyzed data from Optum's 2019 biannual clinician survey, including a validated burnout measure and measures of provider experience and intent to stay. A 6-item measure of team effectiveness (TEAM) focused on efficiency, communication, continuous improvement, and leadership. Construct validity was assessed with content, reliability, and correlation with burnout. Generalized estimating equations with robust SEs determined relationships among TEAM score, provider experience, and intent to stay, controlling for demographics, clustering, and practice factors. RESULTS: Of 1500 physicians and advanced practice clinicians (1387 with complete data; response rate 56%), there were 58% in primary care; 57% were women, and 38% identified as Asian, Black/Hispanic, or another race/ethnicity other than White non-Hispanic. Burnout was present in 30%. The Cronbach α was excellent (0.86), and TEAM correlated with the validated burnout measure (adjusted odds ratio [OR] of lower burnout with high TEAM score, 0.28; 95% CI, 0.19-0.40; P < .0001). Clinicians with TEAM scores of at least 4 were more likely to have positive provider experiences (79% favorable vs 24% with low TEAM score; P < .001), had lower burnout rates (17% vs 44%%; P < .001), and more often intended to stay (93% vs 65%; P < .001). TEAM index score was strongly associated with provider experience (adjusted OR, 11.72; 95% CI, 8.11-16.95; P < .001) and intent to stay (adjusted OR, 7.24; 95% CI, 5.34-9.83; P < .001). CONCLUSIONS: The TEAM index is related to provider experience, burnout, and intent to stay, and it may help organizations optimize clinical work environments.

Body mass index at different adult ages, weight change, and colorectal cancer risk in the National Institutes of Health-AARP Cohort.

The authors investigated the relations of body mass index at different ages and adult weight change to incident colorectal cancer risk in the prospective National Institutes of Health-AARP Diet and Health Study (1995-1996), using a subcohort with repeated recall weights (273,679 participants; mean baseline age = 62.8 years). During 2,509,662 person-years follow-up, 4076 incident colorectal cancers were ascertained. For men, an increased risk of colon cancer but not rectal cancer was associated with body mass index at baseline age (per 5-kg/m(2) increase, hazard ratio (HR) = 1.18, 95% confidence interval (CI): 1.11, 1.25), at age 50 years (HR = 1.18, 95% CI: 1.10, 1.26), and at age 35 years (HR = 1.16, 95% CI: 1.07, 1.25) but less so at age 18 years. Weight gained between the ages of 18 and 35 years and between 18 years of age and the baseline age was associated with an increased risk of colon cancer in men (per 0.5-kg/year increase, HR = 1.18, 95% CI: 1.11, 1.25 and HR = 1.29, 95% CI: 1.16, 1.56, respectively). For women, relations throughout were weaker than those observed for men. These findings suggest that weight gains during early to middle adulthood have important influences on colon cancer risk, especially in men.

Association between major patterns of dietary intake and weight status in adolescents.

The relationship between dietary intake and obesity is complex, and dietary pattern analysis may offer new insight. We examined associations between dietary patterns identified in a diverse cohort of adolescents and weight status cross-sectionally and over a 5-year period. Project EAT (Eating Among Teens) (Time 1) collected data on 4746 middle (younger cohort) and high school (older cohort) students in 1998-9. EAT-II (Time 2) resurveyed 2516 of the original cohort in 2003-4. All analyses were run separately by age cohort and sex. The relationship between dietary patterns identified previously (vegetable, fruit, vegetable & fruit, starchy food, sweet & salty snack food, and fast food) and weight status was examined using logistic regression. All analyses were adjusted for socioeconomic status, race/ethnicity and activity level (longitudinal analyses were also adjusted for baseline weight status). In cross-sectional analyses, higher adherence to dietary patterns loading heavily on vegetables was associated with lower risk of overweight/obese weight status in older and younger girls, whereas higher adherence to a 'sweet & salty snack food' pattern was associated with lower risk in older and younger boys. These associations were found prospectively in older boys and girls, but were no longer significant in analyses adjusting for baseline weight status. We did not find consistent or intuitive associations between dietary patterns and weight status. Identified patterns may not capture the elements of diet that are truly important in determining adolescent weight, or diet may not be the primary driver in determining weight status at this age. Methodological difficulties in assessing diet must also be taken into consideration.